fix invalid address deferencing in error message when an invalid connection is requested
fix invalid address deferencing in error message when an invalid connection is requested

jab1982/opennsa,NORDUnet/opennsa,jeroenh/OpenNSA,jeroenh/OpenNSA,jab1982/opennsa,jeroenh/OpenNSA,NORDUnet/opennsa,NORDUnet/opennsa